If the engine cranks but does not start, it may be caused by a tripped inertia switch. Switch the key to "ON" and the fuel pump should be heard running for a second or two. Listen at the gas filler if necessary. The inertia switch is located on the firewall and can be tripped when the parking brake is set too hard and then released. The inertia switch should be reset, and will click when it is reset.
1991 Mazda Navajo Problem Reports
Most Reported 1991 Mazda Navajo Problem Reports
If the engine stalls when coming to a stop and/or has a rough idle, it may be due to sludge accumulation in the throttle body and idle air control valve. The throttle body and idle air control valve will need to be cleaned if there is buildup.
If the engine stalls and/or has a rough idle, it may need a fuel injector cleaning, the early models were subject to injector fouling and need periodic cleaning.
Failure to change the power steering fluid can cause the fluid to become gray with metal particles. The contaminated fluid can damage the power steering pump resulting in a growling noise when the wheel is turned; the damaged pump will require replacement to eliminate the noise.. Life of the power steering gearbox and pump will be shortened if the fluid is not serviced regularly.
The radius arm bushing may wear, causing a clunking or popping noise when driving over bumps. To repair, the bushings need to be replaced. Depending on the severity of the wear, the brackets may also need replacement. Driving with worn bushings will shorten tire life and cause tire cupping (uneven tire wear).
If a noise from the rear end is heard when going around turns or after driving at highway speed for an extended period, this could be caused by a failing deferential clutch kit. An updated differential clutch kit available.
The O-ring seals in the AC couplings can develop leaks. The condenser can also crack and leak, which is sometimes misdiagnosed as a leaking coupling. The condenser cracks out of sight, under the radiator support, so it looks like the coupler is leaking. Leak testing with fluorescent dye will help locate the exact source of the leak.
If you experience difficulty starting the engine when cold, stalling at idle, or hesitations during acceleration, it may be the idle air bypass valve. This valve helps the vehicle idle steady when the accelerator pedal is not pressed.